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Old 02-05-2015, 10:01 PM
  # 94 (permalink)  
oak
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Thanks for posting the answer!

I think it is significant that in the Monty Hall problem, Monty knows where the prize is and will not open the door to the prize.
The Monty Hall page (explanation)
The Monty Hall page (to play the game online)

This is what convinced me that switching was a good idea-
If prisoners A & B are not pardoned, there is a 0% chance that the warden will say that prisoner C will not be pardoned.
If prisoners B & C are not pardoned, there is a 50% chance that the warden will say that prisoner C will not be pardoned. (and a 50% chance that the warden will say that prisoner B will not be pardoned)
If prisoners A & C are not pardoned, there is a 100% chance that the warden will say that prisoner C will not be pardoned. (Assumption: The warden will not tell prisoner A that he will not be pardoned.)
The above three combinations have an equal chance of happening (1/3 chance for each option). Although we know that the first combination did not happen (A & B are not both not pardoned), since C is not pardoned.

I used Bayes theorem, which gives the correct answer (although I might be using Bayes theorem incorrectly).
Bayes' theorem - Wikipedia, the free encyclopedia (Look at the "Introductory Example" section)


How did other people come to an answer???
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